What is money?
One way to look at it: An interface between an individual and his surrounding society, to manage resources and the production and distribution of goods and services.
Even simpler perspective: Measure of value. The typical price of a good is derived from the value of resources/inputs that went into making it. The value of the inputs themselves is based on patterns of their scarcity or availability.
Specific models of money currently under use? Apart from the marginal bitcoins, and so on, virtually all economic transactions use a debt-based monetary system.
[ Separate section for Debt-based money and its implications..
debt-based implies that scarcity of money is inherent in the design itself.
In which case, it would be incorrect to map the value of all resources into monetary terms.. especially those resources which are potentially abundant, and not scarce at all.
Today, our economic model actually tries to suppress the true abundant nature of some resources, just so that they can be continued to be monetized.
Direction of Causality:
Presupposed scarcity of life-support
=> monetization of resources happens
=> people deem it necessary to keep earning to feed themselves
=> people feel the need to maintain and uphold the monetary value of their own jobs
=> society tends to preserve the scarcity of life-support, because that is only how they can survive
If one refuses to exit this loop, one would also fail to perceive the possibility of what lies beyond the domain of this loop: abundance! [separate section on abundance]